Returns the row associated with a given item.
Original signature is '- (NSInteger)rowForItem:(id)item'
Available in Mac OS X v10.0 and later.


- item (Id)
- An item in the receiver.

The row associated with item, or –1 if item is nil or cannot be found.

- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)